Polyurethanes containing amino organosilane modified clay

ABSTRACT

The instant disclosure is directed to the polyurethane polymer compositions which are filled with a kaolin clay which has been modified with from 1% to 3% of an amino organosilane. The modulus and tear resistance of the polymers is improved without degradation of the remaining properties.

This invention relates to polyurethane polymer compositions containing finely divided amino organosilane modified kaolin clay fillers.

The present application is a continuation-in-part of applicant's copending application Ser. No. 269,695, filed Apr. 1, 1963, now Patent No. 3,290,165, entitled, "Surface Modified Pigments," which in turn is a continuation-in-part of applicant's application Ser. No. 189,321, filed Apr. 23, 1962, entitled, "Surface Modified Pigments," now abandoned.

Polyurethane polymer compositions can be formed from a variety of polymers, l.e., thermosetting gums, thermoplastic polymers and liquid or casting polymers. The preparations for various classes and grades of polyurethanes are well known in the art and need not be detailed here; however, the general reaction by which they are formed is by a chain extension process rather than the usual polymerization reaction. In this process a relatively short chain polymer, either a polyester or a polyether, is reacted with an organic diisocyanate to form long chain urethane polymer. The process variations and polymerization variations caused thereby result in a multitude of compositions all broadly falling in one of the three classes mentioned.

The polyurethanes have several outstanding properties which make them desirable products, chief among them is abrasion resistance, good low temperature characteristics, good resistance to heat deterioration, ozone cracking, weathering, and oil or solvent swelling.

Thermosetting gum vulcanizates have a variety of uses in conveyor belts, roll covers, sandblast-hose tubes and other applications where good abrasion resistance is needed.

Thermoplastic resins can be processed on standard extrusion, injection molding, and transfer molding equipment. These resins are useful in small parts such as mallet heads, sprocket gears, adhesive coatings and unsupported sheetings such as fuel tanks, tarpaulins and chute liners.

Liquid polyurethane valcanizates exhibit good abrasion resistance, non-marking and a wide range of hardnesses. These products have use in large rolls for the steel industry, fork lift truck wheels, ladies toplifts, ball-joint seals, automotive seals, potting compounds, conveyor belts, V-belts, and tank linings.

Despite the fact that the polyurethanes have outstanding properties and are suitable for a large variety of uses, industry is constantly attempting to improve them by various means. Properties which are desirable to improve are modulus, tear resistance, hardness and abrasion resistance. In many cases reinforcing fillers have been tried but on the whole, while some improvements resulted, the degradation of other properties resulted and a completely satisfactory filler has not been found.

It is an object of this invention to provide solid polyprethane vulcanizates and thermoplastic resin compositions containing reinforcing fillers of modified kaolin clays.

Other objects and advantages will be apparent from the following specification.

I have discovered that kaolin clay modified with saturated amino organosilanes are reinforcing fillers for polyurethane polymers and impart improved properties to them. Particularly, modulus and tear resistance are improved with little, if any, degradation of other important properties.

The kaoline clays which are suitable as substrates for the modifier are refined clays of the rubber and paper grades.

The modified kaolin clays can be prepared by dissolving the desired amount of amino organosilane in a suitable solvent, adding the pigment and heating until the reaction is complete. The amount of modifier added depends upon the specific modifier used and the intended polymer to be reinforced. Generally from 1% to 3% by weight of the modifier is sufficient for most purposes.

A particularly useful process for modifying the kaolin clay involves spray drying kaolin slurries having one or more of the amino organosilanes dispersed therein. The spray drying process effects a uniform distribution of the modifier on the kaolin. Another satisfactory method of modifying the kaolin involves dissolving the desired amount of amino organosilane in a suitable solvent, adding the kaolin and heating until the reaction is complete.

The compounds used to modify the kaolin clays can be depicted by the formula: ##STR1## wherein R₁ is hydrogen, alkyl, aryl, cycloalkyl, or alkylaryl; R₂ is hydrogen, alkyl, aryl, cycloalkyl, or alkylaryl; R₃ is hydrogen, lower alkyl, aryl, lower alkylaryl, or lower arylalkyl; R₄ is hydrogen, lower alkyl, aryl, lower alkylaryl, or lower arylalkyl; R₅ is hydrogen, lower alkyl, aryl, lower alkylaryl, or lower arylalkyl; and X is alkylene, alkylene containing secondary amino nitrogen, alkylene containing tertiary amino nitrogen, arylene, arylene containing secondary amino nitrogen, arylene containing tertiary amino nitrogen, alkylarylene, alkylarylene containing secondary amino nitrogen, alkylarylene containing tertiary amino nitrogen, arylalkylene, arylalkylene containing secondary amino nitrogen, arylalkylene containing tertiary amino nitrogen, cycloalkylene, cycloalkylene containing secondary amino nitrogen and cycloalkylene containing tertiary amino nitrogen. Some of these amino organosilanes are disclosed along with methods for their preparation in U.S. Patents Nos. 2,832,754, 2,930,809, 3,007,957, and 3,020,302. Commercially available amino organo silanes useful in the practice of this invention include "A-1100," a gamma-aminopropyltriethoxy silane (GAPTS), and "Y-2967," an amino organosilane which is a modified gamma-aminopropyltriethoxy silane, sold by Union Carbide Corporation, New York, N.Y., "Z-6020," a diamino functional silane, sold by Dow Corning Corporation, Midland, Michigan.

Representative commercially available polyurethane polymers suitable for use in this invention are "Vibrathane 5003," a thermosetting gum which is cross-linked, produced by Naugatuck Chemical Division of U.S. Rubber Company; "Elastothane 455," a thermosetting gum which is cross-linked, produced by Thiokol; "Genthane S," a cross-linked thermosetting gum produced by General Chemical; "Estane," a thermoplastic resin produced by B. F. Goodrich Chemical; "Texin," a thermoplastic resin produced by Mobay; "Multrathane," a liquid polymer produced by Mobay; "Cyanoprene 4590," a liquid polymer produced by American Cyanamid; "Adiprene L," produced by Du Pont; "Vibrathane 6000," produced by Naugatuck; and "Neothane," produced by Goodyear.

In the following formulations the gums were mill-mixed or Banbury-mixed and the thermoplastic resins were mill-mixed and injection molded.

The following formulations illustrate this invention.

Example I

    ______________________________________                                                             Parts                                                      ______________________________________                                         Vibrathane 5003       100                                                      Stearic acid          0.25                                                     Dicup 40C (polymerizing agent)                                                                       5                                                        Filler (modified clay)                                                                               60                                                       ______________________________________                                    

The compounds were mixed on a 6 inch by 12 inch laboratory mill and cured for 30 minutes at 307° F., except for the NBS abrasion test where the cure was for 60 minutes at 307° F.

The data tabulated in Table I indicates the results when 1%, 2% and 3% by weight of GAPTS modified kaolin clay and 1% by weight Silicone Z-6020 modified kaolin clay is the filler.

                                      TABLE I                                      __________________________________________________________________________                               1%    2%    3%    1%                                                           GAPTS GAPTS GAPTS Z-6020                                              Control                                                                             Kaolin                                                                             on Kaolin                                                                            on Kaolin                                                                            on Kaolin                                                                            on Kaolin                          __________________________________________________________________________     Parts Filler/100 parts Polymer                                                                  None 60  60    60    60    60                                 Tensile, p.s.i.  3,500                                                                               (.sup.1)                                                                           3,920 3,600 3,840 3,270                              Stress 300%, p.s.i.                                                                             1,040                                                                               (.sup.1)                                                                           2,600 3,390 --    2,520                              Elongation, percent                                                                             440  (.sup.1)                                                                           470   350   265   365                                Shore A Hardness 58   --  74    74    74    73                                 NBS Abrasion, percent of Standard                                                               100  --  89    134   157   193                                Minutes Cured at 305° F.                                                                 30   30  30    30    30    60                                 __________________________________________________________________________      .sup.1 No cure.                                                          

Example II

    ______________________________________                                                       Parts                                                            ______________________________________                                                Texin 480A                                                                              100                                                                   Modified clay                                                                           20                                                             ______________________________________                                    

The resin was molded at 390°-410° F. and post cured at 110° C. for 24 hrs. The results are tabulated in Table II.

                  TABLE II                                                         ______________________________________                                                                        1%                                                                Con-  Kao-   GAPTS                                                             trol  lin    on Kaolin                                       ______________________________________                                         Parts Filler/100 parts Polymer                                                                     None    20     20                                          Stress 300%, p.s.i. 1,720   2,170  2,430                                       Tensile, p.s.i.     5,700   2,540  2,620                                       Elongation, percent 640     510    400                                         Shore A Hardness    75      78     78                                          NBS Abrasion, percent of Standard                                                                  100     77     92.5                                        ______________________________________                                    

Example III

    ______________________________________                                                        Parts                                                           ______________________________________                                                Texin 480A                                                                              100                                                                   Modified clay                                                                            20                                                            ______________________________________                                    

The resin was molded at 390°-410° F. and was not post cured. The results are shown in Table III.

                  TABLE III                                                        ______________________________________                                                               0.25%    0.5%   1%                                                             GAPTS    GAPTS  GAPTS                                             Con-  Kao-   on       on     on                                                trol  lin    Kaolin   Kaolin Kaolin                                   ______________________________________                                         Parts Filler/100                                                                          0       20     20     20     20                                     parts Polymer                                                                  Stress 300%, p.s.i.                                                                       1,090   1,680  1,725  1,735  1,720                                  Tensile, p.s.i.                                                                           4,380   4,470  3,340  4,250  4,400                                  Elongation,                                                                               610     640    560    655    595                                    percent                                                                        Shore A Hardness                                                                          85      88     88     88     88                                     ______________________________________                                    

Example IV

    ______________________________________                                                       Parts                                                            ______________________________________                                         Estane 5701     100                                                            Barium stearate  3                                                             Modified clay   25 or 50                                                       ______________________________________                                    

The resin was molded 5' at 350° F. held in the mold under pressure until the temperature dropped below 200° F. The results are tabulated in Table IV.

                  TABLE IV                                                         ______________________________________                                                        Con-            Kaolin plus                                                    trol  Kaolin    1% Z 6020                                       ______________________________________                                         Parts Filler/100 parts Polymer                                                                  0       25     50   25   50                                   300% Modulus, p.s.i.                                                                            1,220   1,580  1,640                                                                               2,840                                                                               3,300                                ASTM Test "Die" C, lbs./in                                                                      410     500    300  560  580                                  NBS Abrasion Index, percent                                                                     492     521    720  1,285                                                                               16.72                                NBS Abrasion Shore A                                                                            82      90     92   90   92                                   ______________________________________                                    

Example V

    ______________________________________                                                      Parts                                                             ______________________________________                                         Estane 5701    100                                                             Barium stearate                                                                                3                                                              Filler         25, 50 or 100                                                   ______________________________________                                    

The polymer batch was treated as in Example IV. The results are shown in Table V.

                                      TABLE V                                      __________________________________________________________________________                      Kaolin                                                                              Kaolin                                                                              Kaolin                                                                              Kaolin  Kaolin                                                                              Kaolin   Kaolin                                                                             Kaolin                          Con-                                                                              Kao-                                                                              plus 2%                                                                             plus 2%                                                                             plus 3%                                                                             plus 1%                                                                             Kao-                                                                              plus 2%                                                                             plus 1%                                                                             Kao-                                                                              plus                                                                                plus 1%                         trol                                                                              lin                                                                               GAPTS                                                                               GAPTS                                                                               GAPTS                                                                               Z 6020                                                                              lin                                                                               GAPTS                                                                               Z 6020                                                                              lin                                                                               GAPTS                                                                               Z                    __________________________________________________________________________                                                               6020                 Parts Filler/100 parts                                                                    0  25 25   25   25   25   50 50   50   100                                                                               100  100                  Polymer                                                                        200% Modulus, p.s.i.                                                                      860                                                                               -- --   --   --   --   1,700                                                                             3,500                                                                               3,740                                                                               -- --   --                   300% Modulus, p.s.i.                                                                      1,440                                                                             1,780                                                                             2,940                                                                               3,260                                                                               3,040                                                                               3,000                                                                               -- --   --   -- --   --                   Shore A Hardness                                                                          88 93 91   92   91   91   94 94   95   97 97   97                   NBS Abrasion, Index                                                                       460                                                                               641                                                                               827  703  641  746  624                                                                               936  568  334                                                                               553  575                  __________________________________________________________________________

Example VI

    ______________________________________                                                       Parts                                                            ______________________________________                                         Estane 5701     100                                                            Barium Stearate  3                                                             Pigment         25 or 50                                                       ______________________________________                                    

The recipe was treated the same as in Example IV. The results are shown in Table VI.

                  TABLE VI                                                         ______________________________________                                                               Kaolin       Kaolin                                                            plus         plus                                                  Con- Kao-   2%           1%                                                    trol lin    GAPTS        Z-6020                                      ______________________________________                                         Parts Filler/100                                                                           None   25     50   25   50   25   50                               parts Polymer                                                                  300% Modulus,                                                                              1,220  1,580  1,640                                                                               2,880                                                                               3,600                                                                               2,840                                                                               3,300                            p.s.i.                                                                         ASTM Tear "Die                                                                             410    500    500  550  480  560  580                              C," lbs./in                                                                    NBS Abrasion,                                                                              492    521    720  1,015                                                                               1,411                                                                               1,285                                                                               1,672                            Index percent                                                                  NBS Abrasion,                                                                              82     90     92   90   91   90   92                               Shore A Hardness                                                               ______________________________________                                    

Example VII

    ______________________________________                                                      Parts                                                             ______________________________________                                         Estane 5701    100                                                             Barium Stearate                                                                                3                                                              Filler         10, 20, 60 or 100                                               ______________________________________                                    

The recipe was treated as in Example IV. The results are shown in Table VII.

                                      TABLE VII                                    __________________________________________________________________________                     Con-                                                                               Kaolin Plus                                                                           Kao-                                                                               Kaolin Plus                                                                           Kao- -trol 1% Z-6020 lin 1%                                                    Z-6020 lin                               __________________________________________________________________________     Parts Filler/100 parts Polymer                                                                 0   10 20  20  60 100 100                                      300% Modulus, p.s.i.                                                                           1,280                                                                              2,040                                                                             2,740                                                                              1,640                                                                              3,420                                                                             --  2,040                                    ASTM Tear "Die C," lbs./in                                                                     420 500                                                                               600 530 540                                                                               406 510                                      NBS Abrasion, Index percent                                                                    570 867                                                                               1,095                                                                              957 1,722                                                                             1,465                                                                              717                                      NBS Abrasion, Shore A                                                                          84  85 89  89  94 95  95                                       __________________________________________________________________________

Example VIII

    ______________________________________                                                             Parts                                                      ______________________________________                                         Adiprene L-100        100                                                      Methylene-bis-orthochloraniline                                                                      11                                                       Pigment               20                                                       ______________________________________                                    

The mixture was cured for 180 minutes at 212° F. The results are shown in Table VIII.

                  TABLE VIII                                                       ______________________________________                                                                         Kaolin                                                                         Plus 1%                                                        Control                                                                               Kaolin   Z-6020                                         ______________________________________                                         Parts Filler/100 parts Polymer                                                                   0        20       20                                         300% Modulus, p.s.i.                                                                             1,530    --       1,940                                      Tensile, p.s.i.   2,570    1,310    2,710 -Elongation, Percent 495 285 480                                         5                                          Shore A Hardness  87       88       90                                         ASTM Tear "Die C," lbs./in                                                                       450      408      505                                        NBS Abrasion, Index Percent                                                                      224      126      194                                        ______________________________________                                    

The examples and data indicate that when the modified kaolin clays useful in this invention are used as fillers in thermosetting gum polyurethanes increases in modulus, hardness and abrasion resistance occur. The remaining properties of the polymer remain within acceptable levels. When these fillers are used to reinforce thermoplastic resins, increases in modulus, tear resistance, and abrasion resistance occur while the remaining polymer properties remain within acceptable levels. When these modified kaolin clay fillers are used to reinforce liquid polymers, increases in modulus, tensile strength, hardness, and tear resistance occur while the remaining properties of the polyurethane remain within acceptable levels. In all the polymers tested the general level of performance of the modified kaolins was superior to the unmodified kaolins.

The foregoing is illustrative only and additional modifications may be made without departing from the substance of the invention as defined in the appended claims. 

I claim:
 1. A polyurethane polymer composition containing as a filler, modified kaolin clay, said kaolin clay .Iadd.having been .Iaddend.modified .Iadd.by treatment .Iaddend.with from 1% to 3% by weight with an aminoorganosilane of the formula ##STR2## wherein R₁ is selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, and alkaryl, R₂ is selected from the group consisting of hydrogen, alkyl, aryl, cycloalkyl, and alkylaryl, R₃ is selected from the group consisting of hydrogen, lower alkyl, aryl, lower alkylaryl, and lower arylalkyl, R₄ is selected from the group consisting of hydrogen, lower alkyl, aryl, lower alkylaryl, and lower arylalkyl, R₅ is selected from the group consisting of hydrogen, lower alkyl, aryl, lower alkylaryl, and lower arylalkyl, and X is selected from the group consisting of alkylene, arylene, alkylarylene, arylalkylene, cycloalkylene, cycloalkylene containing secondary amino nitrogen and cycloalkylene containing tertiary amino nitrogen.Iadd., the modification of said kaolin clay being carried out by spray drying kaolin slurries having one or more of said amonoorganosilanes dispersed therein, said spray drying effecting a uniform distribution of said aminoorganosilane on the kaolin. .Iaddend.
 2. The composition of claim 1 wherein the filler is kaolin clay modified with from 1% to 3% by weight of a diamino functional silane.
 3. The composition of claim 1 wherein the filler is kaolin clay modified with 1% to 3% by weight of gamma-aminopropyltriethoxysilane. .Iadd.
 4. A polyurethane polymer composition containing as a filler, modified kaolin clay, said kaolin clay having been modified by treatment with from 1% to 3% by weight of an aminoorganosilane of the formula:

    H.sub.2 N--R--Si--(OR').sub.3

wherein R is selected from the group consisting of phenylene, lower alkyl substituted phenylene, lower alkoxy substituted phenylene, and lower alkylene, R' is a monovalent hydrocarbon group free of aliphatic unsaturation selected from the group consisting of lower alkyl, aryl, lower alkaryl and lower aralkyl, and wherein R' can represent the same or different groups. .Iaddend. 